1. Field of the Invention
The present invention relates to a tool mounting device for a turning center that can suitably exchange rotating tools and turning tools to perform milling and cutting (turning).
2. Background Art
In a turning center, a mounting engagement unit for engaging a tapered shank provided to the base end of a tool is disposed on a main shaft that is rotatably mounted on a ram via a bearing unit. A clamp mechanism is disposed for clamping a clamping convexity of the tapered shank by retracting the drawbar, and drawing/engaging the tapered shank to the mounting engagement unit to detachably/replaceably mount and fix a tool to the main shaft, so as to allow the shaft to be clamped and released based on the reciprocating control of the drawbar. Tools are suitably attached and detached using the shared clamping mechanism, and rotating tools are rotatably clamped/fixed together with the main shaft. When turning tools are clamped/fixed, the tools are baffled and fixed together with the main shaft; and rotating tools and turning tools can thereby be suitably exchanged and mounted, and both milling and cutting can be carried out.
In such a turning center, when the clamp mechanism of the rotating tools and turning tools is configured so as to be shared as described above, the radial load on the turning tools is considerably greater than on the turning tools, and the clamp force must therefore be increased. In order to do so, however, a hydraulic cylinder device with a large diameter for outputting a considerable drive force must be used, and there are configurations in which a hydraulic two-stage cylinder is used.
Since a hydraulic cylinder device is therefore necessarily required, an oilless structure cannot be obtained and energy and resources cannot be saved.
On the other the hand, for example, a wedge mechanism (Japanese Laid-open Patent Application No. 2004-202659) developed by the applicant, and other mechanisms capable of withstanding a considerable cutting force even if an air cylinder device is used are difficult to mount in a turning center because of the need to rotatably clamp and fix a rotating tool in the turning center and because a shared clamp mechanism is provided for clamping/fixing rotating tools and turning tools.
[Prior Art 1] Japanese Laid-Open Patent Application No. 2004-216536
[Prior Art 2] Japanese Laid-Open Patent Application No. 2004-202659
[Prior Art 3] Japanese Laid-Open Patent Application No. 2004-50324